Emails not displaying properly

Hi,

On my MacBook, I have Outlook installed and the email is displayed exactly how it’s configured.

https://imgur.com/a/GRZOvYR

On my clients PC, up until 10 days ago, emails were being displayed perfectly in Outlook.

For the past 10 days, the email is not displayed properly in that the columns are not displayed side by side how they should be.

Instead, they’re displayed in a linear fashion which is not good..

https://imgur.com/a/R2qKMCB

How can I fix this?

Also, when I go to forward the email the view switches too like this:

https://imgur.com/a/GD45362